Y
by Angel Sciuto
Summary: The BAU are called to Miami & debate is sparked over the controversial "serial killer chromosome".
1. Chapter 1

_**I know I haven't updated most of my stories (I will update as soon as inspiration hits). This is just a short story probably only going to be a few chapters long. Got the idea while watching season six of CSI Miami on DVD. Hope you like it & I only own the made-up characters, i.e. victims random cops etc.**_

Criminal Minds/CSI: MIAMI x-over.

Y.

Chapter 1: Innocence.

Miami, Florida.

Joshua Gordon smile to himself as he walked home from school. For once his parents would be proud of him. As he fumbled in his pockets for his house key he suddenly felt something tight around his neck. Everything went black as he tried to remove the noose around his throat.

When he came to, Joshua could feel that his hands and feet had been tied behind is back. He struggled to move and fell off the couch he had been placed on. He groaned and found he'd been gagged as well. Joshua heard a noise beside him and looked up to see where it had come from. His parents were tied up just like he was. His mother was crying. He noticed someone standing behind them. Someone he didn't recognise. The man walked towards his parents with something behind his back. Before Joshua could look away, the man used a butcher knife to slash both of his parents' throats from ear to ear. Joshua couldn't help but scream. A scream nobody ever heard. Before he could even open his mouth the man had grabbed a hand over it and ripped the blade through his throat from one ear to the other.

8 hours later...

"Frank, what have we got?" Detective Frank Tripp looked up.

"It's a bit of a mess in there, H. Parents and son all with their throats slashed from ear to ear. Nobody heard a thing. Neighbour called it in. They were supposed to be going over for dinner, when the neighbour couldn't raise anyone on the phone she sent her husband over to check it out, he rushed back and called it in." He replied.

"Do we know if anyone else lives in the house, Frank?"

"No, everyone that lives there is gunna be going home with Alexx. We're trying to get in contact with the mother's sister. So far we haven't had much luck."

"Keep trying, Frank." As Frank headed off to help the patrol cops, Lieutenant Horatio Caine walked inside.

"Alexx, what have we got?" Medical Examiner Alexx Woods looked up at the sound of Horatio's voice.

"It's a massacre Horatio. This boy is only 11 years old. Who would do something like this to an 11 yr old?"

"I don't know Alexx but I intend to find out."

(Cue MIAMI THEME)

While the rest of the team worked the scene, Horatio followed Alexx back to the morgue.

"This is the fourth family massacre in a month. Horatio, I hate to say it but I think we have ourselves a serial killer."

"I agree Alexx. Which means we need to work fast before he kills again."

"Everything is the same as the others. You know Horatio, you may some help with this one." Alexx looked at him through the plastic face covering she was wearing.

"Any ideas, Alexx?" She smiled

"Now, honey, I can't solve everything for you."

Horatio smiled as he walked out.

"H! Managed to catch the sister she's flying in from Chicago tonight. Caught the first available flight. Should I send someone to meet her?" Frank just managed to catch Horatio at the elevator.

"Good idea, Frank. Keep me posted." Frank nodded as the elevator doors shut.

Horatio walked into his office and shut the door. He sat down at his desk. The files of each of the families sat piled one on top of the other in front of him. The newest at the top. Horatio reached into a drawer and pulled out a card with a phone number and email address on it. He scanned the files into the computer and opened up his email and entered the address into a new message. He added the files, wrote a short message and clicked send. He picked up the phone and dialled the number.

"Agent Jareau? This is Lt. Horatio Caine from Miami Dade Police Department. I've just sent you an email containing the files of a case I currently have that is building way too fast. I would appreciate it if you and your team could take a look."

"I'll take a look and see what the team thinks. I'll call you back to let you know whether we're going to take the case." Came the answer.

"Thank you, ma'am." As he hung up, the door opened.

"H, we finally finished at the scene. It's the same as the others. Killer left nothing behind. All the blood belongs to the vics. Calleigh's checking everything for prints but so far there's none. Valera is running all of the blood just in case but we're not likely to find anything."

"Thank you Eric. Frank has someone meeting the sister at the airport. Talk to her see what she knows. Excuse me." Horatio added as the desk phone rang. Eric nodded and left.

"Agent Jareau, thank you for getting back to me so quickly."

"We're just heading to the jet hanger now we should be in Miami in a couple of hours. We'll go over the case on the plane."

"Thank you. I will meet you at the airport myself."

One hour previous

Washington, DC, Virginia.

Special Agent Jennifer Jareau was quietly sitting at her desk, absentmindedly staring at the photo of her, Will & their son Henry when her phone rang.

"Agent Jareau? This is Lt. Horatio Caine from Miami Dade Police Department. I've just sent you an email containing the files of a case I currently have that is building way too fast. I would appreciate it if you and your team could take a look."

"I'll take a look and see what the team thinks. I'll call you back to let you know whether we're going to take the case." JJ answered.

"Thank you, ma'am."

JJ printed out the case files and headed out of her office.

"Hotch? We've got a new case in Miami. Families being massacred in their homes."

Special Agent Aaron Hotchner looked up.

"Ok, I'll gather everyone in the conference room." JJ nodded and headed back to her office to make copies of the files for the rest of the team. When she walked into the conference room everyone was waiting.

"Miami. They've had four families massacred in their homes in a month. The latest family the Gordons were murdered sometime last night. Each of the families had a young son ages between 9 and 13. The only other similarities were the MO, slashing their throats from ear to ear, and the fact that the killer left nothing of himself behind. Lt Caine has asked if we could take a look and help him out before this guy strikes again."

"Wow, look at how he kills them. According to the autopsy reports he kills the parents first, probably makes the kid watch. Then, before the kid can react he kills the kid too. Question is what did these families do that pissed this guy off?" Special Agent Derek Morgan shook he head in disgust as he spoke.

"He obviously feels inadequate about something to cut them from ear to ear like that. He might be unable to perform sexually and he gets the thrill he needs by killing them so brutally." Doctor Spencer Reid suggested.

"Yeah, well whatever it is he's not likely to stop on his own. JJ you'd better call Lt Caine back and let him now we'll be there as soon as we can." Hotch said as he gathered his copy of the files. "Everyone ready in ten minutes wheels up in half an hour."

JJ walked back into her office and grabbed her overnight bag. Then she picked up the phone and dialled Lt Caine's number

"Agent Jareau, thank you for getting back to me so quickly."

"We're just heading to the jet hanger now we should be in Miami in a couple of hours. We'll go over the case on the plane."

"Thank you. I will meet you at the airport myself."

(Cue CRIMINAL MINDS THEME).


	2. Chapter 2

_**Here's chapter 2. I don't know whether clothes fibres can change colour under ultra-violet light but if not then bear with me (it was the only way I could make them catch the guy).**_

Chapter 2: Help.

BAU Jet.

"Lt Caine is going to meet us at the airport." JJ said to Hotch as they walked up the gangway.

"I want you to see if you can do your usual tricks with the media. If this hasn't broken as a serial killer case yet, it will soon. The last thing we are going to need is families panicking." JJ nodded as she sat down.

Two hours later

Morgan stuck his head in

"Pilot says we land in five." Hotch nodded. As everyone got comfortable preparing for landing, Hotch gave everyone their duties.

"Morgan, I want you at the first crime scene. Prentiss, the second, Dave the third & Reid, can you work victimology? I'll see if I can talk to some of the victims' next of kin. JJ's going to handle the media. Hopefully we can help Lt Caine catch this guy before he can find his next family."

"Agent Jareau? I am Lt Horatio Caine. We spoke on the phone. Excuse me." He added as his phone rang.

"Eric. Alright. Do you have the address? I am on my way." He hung up the phone and sighed.

"What's wrong?" asked Special Agent Emily Prentiss.

"It seems...it seems that our killer has struck again." Answered Horatio.

"Everyone stick with the planned arrangement. I'll go to the new crime scene with Lt Caine. Keep me informed." Hotch said as they all headed for the cars.

"I don't get it, Calleigh," sighed Eric as he ran his hands through his hair. "How can there be no trace of this guy other than his victims? There's gotta be something he missed!"

"Well if there is, we'll find it Eric. Like Horatio says we just have to follow the evidence. Okay so the only prints I was able to find in the house matched the reference samples from our victims that Alexx took. Same goes for DNA. Valera is still running tests for us just in case we missed something. Do you have any idea where Horatio is?"

"Yeah he said something about meeting the FEDS at the airport."

"FEDS? Why are they getting involved?"

"According to H, it's some team out of DC that only come in on cases if they're invited. The team is made up of profilers. H thinks they might be able to help." Eric explained.

"I hope he's right." Just then Eric's phone rang.

"Delko. Hey Frank, what's going on? Dammit. Alright, does Horatio know? Nah I'll call him. Thanks Frank." As he hung up Calleigh had a curious look on her face.

"What's going on Eric?"

"Our killer struck again. This time on Star Island. I'll meet you there gotta let H know."

"Okay don't forget your kit." Joked Calleigh as she headed out the door.

"I won't it's in the back of my car anyway." Eric chuckled as he pulled out his phone and dialled Horatio's number.

"H?"

"Eric."

"You aren't gunna like this, Frank called our killer struck again."

"Alright. Do you have the address?"

"Yeah, it's on Star Island. Just look for all the cop cars. Calleigh should be there by now. I'll meet you there. Just leaving now."

"I am on my way." Horatio replied and hung up the phone. Eric hoped they'd find something that could help as he headed for his hummer.

When he got to the crime scene, Eric could see Alexx already loading the victims. Calleigh was photographing the blood spatter.  
"Eric do you mind giving me a hand here? I'm trying to determine the directionality of this particular spatter."

"Sure." Eric walked over and held her camera while Calleigh measured the distances from the victims' last lying places to the spatter on the wall.

"DNA will confirm it but I'm pretty sure this blood is the mum's."

"Eric, Calleigh. This is Special Agent Hotchner with the BAU. What have we got please?" Horatio said as he walked in with Hotch close behind.

"Well everything's the same as the first four Horatio. Blood everywhere but I doubt any of it will be our killer's. Alexx is on her way back to the morgue to start the autopsies. I'll print every surface I can but I don't think the killer left any prints behind just like the last four times."

"Ok keep me posted."

"Will do."

A few hours later...

With the scene finally processed, Calleigh and Eric headed back to the lab. Once they had logged all of the evidence and sent it for processing, they joined Horatio in the large conference room. Ryan Wolfe and Natalia Boa Vista were waiting there too. Agent Hotchner was there with a team of his own.

Horatio introduced his team and Agent Hotchner did likewise.

Before anyone could do or say anything, Valera walked in.

"Lt? You may want to see this. I was so busy checking to see if there was any unknown DNA among the blood from the victims that I missed it. It's the same with every family. Each of the sons in each of the families that were killed, had XYY chromosomes. Each of the kids had the killer chromosome."

"Actually, the alleged killer chromosome was disproved in the 1970's. Psychiatrists found that it didn't seem to be any more of a cause of violence than people's upbringing." Reid piped up.

"Maybe the unsub either didn't know that or didn't agree. In which case He might be a psychiatrist or a psychologist. It would explain how he picks his victims. And how he knows which families have children with the extra Y chromosome." Suggested Prentiss. Morgan pulled out his phone.

"That could mean that our unsub is an older guy. I'll have Garcia run all the psychiatrists and psychologists in the Miami area."

"I'm curious. You guys keep referring to the killer as "unsub" what exactly does that mean?" Calleigh asked.

"It means unknown subject. We often forget to explain that." Replied Prentiss.

"Garcia, I need you to run all the psychiatrists and psychologists in the Miami area. Focus on those who would have started practising around the 1970's possibly early 60's. Thanks baby doll. Garcia's gonna let us know." Morgan told the others.

"Maybe Frank should get some guys to canvass the neighbourhoods around where the killings happened. Maybe someone saw something." Suggested Eric.

"The unsub would have had to watch the families for weeks. Get their routine. Someone might have noticed him watching the houses. Morgan, you and Rossi go with them." Hotch delegated.

A few hours later...

"We canvassed each of the neighbourhoods. Nobody noticed anything. I'm starting to think this guy is a phantom, Horatio." Frank said as he put his notepad back in his pocket.

"We'll catch him Frank. By the way, we may have jut caught a break in the case. Natalia found some fibres in the blood. Eric's just about to run them through the mass-spec to determine what they are. For all we know they could be the one thing we need to catch this guy. " Calleigh said as she walked past on her way to Trace.

"Wish I had your confidence Calleigh."

Just then Frank's phone rang. Horatio followed Calleigh into the Trace lab.

"Hey H. I'm just about to run the sample now. I've already looked at them under the microscope. The fibres are navy blue when you get them under the microscope but here's the funny thing. I ran them under an ultra-violet light and the colour changed! Under the ultra-violet light the fibres turned bright red. Hopefully the mass-spec should tell us why."

"Maybe we won't need it to." Calleigh interrupted.

"Calleigh, why would you say that?" Horatio was curious.

"Designers have started using this new material. It's really popular in clubbing scenes. See because the clubs use strobe lights and ultra-violet lights, the patrons' clothes can change colour. Although I don't think our killer would be the clubbing type." Just then the mass-spec beeped. As Eric looked over the results, Frank walked in, putting his phone in his pocket as he did so.

"We may have caught a break in the case, Horatio."

"What makes you say that, Frank?" asked Eric with a smirk.

"Kid that lives up the road from the fourth family may have seen something. I'm headed over there now to see what I can find out."

"We'll come with you." Said Hotch, as he and Reid entered the room behind him.

"Well that's all good but you didn't break the case Frank. Natalia did by finding fibres that might be from the killer's clothing." Eric baited him.

"Whatever. As long as we catch this guy." Frank rolled his eyes. Frank headed out the door and Hotch and Reid followed him.

"Keep me posted, Frank." Horatio added as they left.

Just as they got into the car Hotch's phone rang.

"Hotch. Hang on Morgan, I'll put you on speaker."

"Garcia got that list we needed. She narrowed it down to four. A Dr Andrew Sharp, a Dr Marlon Henderson, a Dr Tiberius Manteezi and a Dr Samuel Dalton. All of them have offices within walking distance of each other. Rossi and I are going to check it out."

"I'll send Prentiss and JJ to help you. We're headed to the house of a kid who may have seen our unsub. Let us know what you find. You may want to let Lt Caine know what you've found." Hotch hung up the phone just as they pulled up to the house.

They knocked on the door and stood back to wait for someone to answer.

"Can I help you?" A voice asked. The woman standing there had a young boy behind him.

"I'm Detective Frank Tripp. These are Agent Hotchner and Dr Reid of the FBI. We spoke on the phone, you said your boy had possibly seen something that might help us." The woman nodded.

"Come in. He's through here."

They followed her in and were temporarily surprised at what they saw....


	3. Chapter 3

_**Here's chapter 3. Just in case you forgot I only own the made up characters. Hope you enjoy.**_

Chapter 3: Clues and Answers.

As they walked into the room they noticed a young boy sitting in a wheelchair, his back to them staring out the window.

"Julian, the police are here to talk to you about hat you saw." His mother said quietly.

Julian wheeled himself around to face them.

"You're trying to catch the guy that killed Josh and his parents. I think I may be able to help you. Josh and I were friends. He confided in me some things I wish I had of told someone before he was murdered."

Hotch smiled to himself. Julian reminded him, personality wise, of a young Reid.

"What exactly did he tell you?" asked Frank.

"He told me that his parents had recently started sending him to a psychologist. You see, I don't know whether you've been told this but Josh was, well, troubled. He wasn't too good at school work, I was trying to help him with that, and he would get into fights at school. His parents thought that he needed to talk to someone. But while he didn't mind going to a psychologist, because he believed it was actually beneficial, he was somewhat wary of the psychologist they'd chosen for him." Julian sighed. It was clear he seemed to blame himself for the fact that his friend was dead.

"Wary how?" asked Reid.

"Well, according to Josh, the very first session he had with the man, and unbeknownst to his parents, the psychologist demanded a blood test. Wouldn't explain to Josh why he wanted it and after it came back he wouldn't tell Josh the results but suddenly started asking very personal questions." Explained Julian.

"Isn't that a psychologist's job to ask personal questions?" quipped Frank.

"Yes, but according to Josh, this guy started asking questions about his home life that wasn't normal. Questions that focused more on what times his parents were home, what kind of jobs his parents had, whether they had time for the gym or the gun range things like that. Josh tried getting the conversations back to normal questions but every time he tried the guy would get really annoyed so Josh just answered him as best he could. Now I'm thinking that him and I should have told someone." Julian told them.

"It's not your fault, Julian. This man would have killed them anyway." Hotch told him. "We should talk to friends of some of the other boys that were killed maybe they went to the same psychologist. Call Lt Caine let him know what we've found. He may be able to get a warrant for client records. Also get on to Garcia she might be able narrow it down." Reid pulled out his phone while Hotch was talking.

"Garcia, hey it's Reid. Listen we need you to run the names of the children against the four psychologists. We're trying to see if they went to the same one, if they did he could be our killer."

Meanwhile....

"Eric, see if you can get a list of any designers in Miami that use this material." Horatio said as his phone rang.

"Frank. Will do. Thank you." Eric looked up.

"Here we go H. Found it. There are two places that use it. One is a men's suit store. They specialise in hand-tailored suits. Made to order. They're based out of a store on Miami Beach. The other place is mostly for celebrities. They get outfits shipped in from around the world. I'd say our best bet is this place on Miami Beach. Want me to go there?"

"Please. Take Ryan with you. Keep me posted." Eric nodded as he headed out the door.

"Hey Ryan, come on." Ryan raised his hand in acknowledgement and followed him to the car.

When they got to the store, the clerk was just closing up.

"Excuse me. Miami Dade Police Department. We need to talk to a manager." Said Ryan as they approached the young girl.

"Sorry, we're closing up. Maybe if you come back tomorrow." She replied.

"This is very important. One of your clients may be a serial killer and we need to look at your records so that we can catch the guy. So if you don't mind letting us in." Said Ryan, exasperatedly.

"Keira, let them in. I'm sorry about that detectives," said a man as Keira reopened the door. "I'm the manager here. What can I help you with?"

"Well we think our killer might possibly get his suits made here and we were wondering if we might be able to look through your records." Eric explained.

"Do you have a warrant?" the man asked.

"Look, man, this guy has brutally massacred five families and may already be planning to kill another. We don't have time to waste! Do you really want to stand here arguing while this guy kills another family?" asked Ryan.

"Fair enough. What are you looking for?"

"He would be ordering more than one at a time. Navy Blue in colour which would become bright red under ultra-violet light."

"Yes I know who you mean. He's a psychologist with a practice not far from here. I deliver the suits there myself personally. Dr Samuel Dalton." As he spoke Eric whipped out his phone.

"Frank, Dr Samuel Dalton, he's our guy. Come on Ryan. Thanks for your help."

Frank, Hotch and Reid walked into the office of Dr Samuel Dalton.

"Hello, can I help you gentlemen?" asked the doctor's secretary.

"We need to speak to Dr Dalton."

"I'm sorry Dr Dalton is with a patient right now. Maybe you should come back later." She replied.

Frank showed her his badge. "Dr Dalton is wanted for questioning in the murders of five families. His patient can wait."

"I'll just go and see if he is willing to see you now." She walked into a room that had a red light next to the door, knocked and waited.

"Enter." Came a loud voice from inside.

"Dr, sorry to interrupt your session, there are detectives from Miami Dade PD that wish to talk to you. They're adamant it can't wait."

"Is that so? Where are they?" was the reply

"Just out here in the waiting room."

"Detectives, if any of you should try to enter this room it will prove fatal. I know you don't want anyone to get hurt so I suggest you leave now and don't return."

"Dr Dalton," called Hotch. "I'm Special Agent Aaron Hotchner with the FBI. We just want to talk." Reid and Frank drew their weapons. Just then they heard a scream. Frank drew out his phone.

"Horatio its Frank. We're gunna need SWAT down here the doc has taken a patient hostage."

"We're on our way Frank." Came the reply.

"Reid get back here." Hotch watched as Reid crept towards the partially open door.

"Dr Dalton. My name is Dr Spencer Reid. I'm with the Behavioural Analysis Unit at Quantico. We don't mean any harm. I think I know why you've been doing this if you want to listen." Reid called out.

"If you don't want anyone to get hurt you'd better leave Dr Reid. I don't care to listen to any of your theories."

"You started your practice back in the seventies when the extra Y chromosome was being blamed for the cause of violence and either a child of yours was diagnosed or maybe a sibling later in life. My guess is that whoever it was acted accordingly and you took that as a betrayal. But it wasn't until recently that you were able to do anything about it. I don't believe that an extra chromosome has anything to do with being violent. Plenty of people are violent without the extra chromosome. Our jails are full with them. So killing those families didn't solve anything. Killing your patient in there won't solve anything either." Suddenly they heard a thump and a cry then a gunshot from inside the room. Then everything was quiet.


	4. Chapter 4

_**So this is the final chapter. It's a little short but I hope you enjoy it.**_

Chapter 4: Justice.

Frank, Hotch and Reid rushed inside to find a young boy standing over the body of Dr Dalton, gun in hand. There was a gunshot wound in Dalton's shoulder and a gash on his forehead.

"It's okay, son. Just place the gun on the ground." Everyone whirled around to see Horatio slowly walking into the room, hands outstretched.

"He was going to kill me. I didn't want to die." The boy sobbed.

"I know. You aren't in any trouble. But we just need you to put the gun down." The boy dropped the gun and it hit the floor with a thud. Frank moved forward and picked it up. Hotch grabbed the boy and moved him out of the room just as Eric, Calleigh and Ryan entered. They looked at the body on the ground.

"At least he won't be able to kill anyone else." Commented Ryan. While Alexx removed the body, the rest of the team documented everything in the room.

A few hours later....

"You know, I could show you around Miami if you'd like? Night out on the town." Ryan said as Prentiss helped him pack up the evidence boxes.

"Em, Hotch says wheels up in an hour." JJ said as she popped her head in.

"Sorry. Looks like we're not staying the night. Maybe next time..." She replied with a smile.

"I appreciate the help, Agent Hotchner." Horatio said.

"Anytime Lt Caine. You have JJ's number. I feel sorry for that poor boy." Hotch replied.

"I, I will see to it that he gets the help he needs." Horatio said as Hotch headed out the door.

"Until next time." He said to nobody in particular.


End file.
